Secondary Pollen Research Articles

Reproductive biology of Santolina ligustica Arrigoni, a rare narrow-ranged species: implications for conservation

Abstract Santolina ligustica is a rare narrow-ranged species endemic to Liguria (Italy) for which a likely trend of decline has been recorded. For this reason, it would be important to assess the reproductive biology of this endemic species. In this study, we investigated the plant–pollinator interactions, the reproductive mode of the plant, and we evaluated both reproductive efficiency and seeds’ germination performances. Santolina ligustica is an obligate cross-pollinating species with a generalist pollination system. The most frequent insects are Coleoptera belonging to the genus Oedemera. Seed set is low, but the seeds germinate under a wide range of temperatures. Taken together, our results indicate that S. ligustica is an insect pollinated and self-incompatible plant, in which low visitation rate, secondary pollen presentation and/or lack of compatible mate may cause a low seed set per capitulum. Nevertheless, the high number of capitula per plant and the high percentage of germination may assure high number of seedlings. Thus, the survival of S. ligustica is probably threatened by other factors such as fragmented distribution and habitat reduction because of land-use change. Under this scenario, we proved that species’ decline is not directly related to reproductive failure and different studies are desirable to provide suggestions for the species conservation.

Biphyly of the genus Wendlandia and establishment of a new tribe Clavistigmateae and a new genus Clavistigma of Rubiaceae from Asia

AbstractWendlandia, as currently circumscribed, is a genus of Rubiaceae comprising about 90 species mainly in tropical and subtropical Asia. By sampling species from all four series (Clavigerae, Euexsertae, Montigenae, Subinclusae) and all tribes in the subfamily Dialypetalanthoideae, we examined the monophyly of Wendlandia based on phylogenetic reconstruction using the nuclear ribosomal internal transcribed spacer and four plastid DNA regions. Wendlandia was resolved as biphyletic, consisting of two distantly related lineages that correspond to the monotypic series Clavigerae (Wendlandia pendula), sister to the Chinese endemic genus Trailliaedoxa, and a clade containing the remainder sampled members of Wendlandia. Based on the isolated phylogenetic position of W. pendula and its unique morphological characteristics compared to the recognized tribes of the Vanguerieae alliance, we herein erect a new monotypic genus, Clavistigma, and a new tribe, Clavistigmateae to accommodate the unique species. The secondary pollen presentation and the unique seed morphology were firstly described for the species. The divergence time between Clavistigma and Trailliaedoxa was dated back to 13.8 mya, coinciding with the climate change in northwestern Yunnan driven by the uplift Tibet Plateau and the river incision in the Hengduan Mountains during the Miocene and Late Pliocene.

Gradual pollen presentation in Vaccinium corymbosum 'Bluecrop': an adaptive mechanism to improve pollination efficiency and outcrossing.

Gradual pollen presentation is a plant reproductive mechanism to improve pollination efficiency and accuracy and promote outcrossing. Vaccinium corymbosum 'Bluecrop' has a typical gradual pollen presentation mechanism. 'Bluecrop' exhibits an inverted bell-shaped flower with a white coloration. By investigating the flower syndrome, pollination characteristics, pollination efficiency, and breeding system of 'Bluecrop', this study aims to explore the adaptive significance of these traits. The results showed 'Bluecrop' released pollen gradually through anther poricidal dehiscence. Among different pollinators, Apis mellifera and Bombus can pollinate effectively, and the mechanism of gradual pollen presentation significantly improved the efficiency of pollen transfer. This characteristic limits the amount of pollen removed by the pollinators and prolongs pollen presentation, thus attracting more pollinators and thereby increasing male fitness. The nectar secretion of 'Bluecrop' is gradual, with a large nectar production and a long phase of nectar secretion, enhance visitation frequencies and the chances of successful pollination. At the same time, campanulate corolla can protect pollen as well as nectar from waste due to environmental factors and other effects. The breeding system of 'Bluecrop' relies mainly on outcrossing because of its low affinity for self-fertilization and good interaction with pollinating insects. Thus, the special floral syndrome and the mechanism of secondary pollen presentation are significant in improving pollination efficiency and promoting the reproductive success of 'Bluecrop' by outcrossing. It can provide a certain theoretical basis for the future propagation breeding of 'Bluecrop'.

Identify The Source of Pollen Feed in Honey and Bee Bread of Tetragonula biroi

This study aims to determine the types of feed pollen consumed by the bee species Tetragonula biroi. The research has the objective of providing information to the public regarding the sources of feed for T. biroi honey bees, which are located in Kuajang Village, Binuang District, Polewali Mandar Regency, West Sulawesi. The research was conducted between February and April 2020. A comparative method was employed to examine the shapes of plant pollen found around the meliponiary in comparison to the shapes of pollen discovered in honey and bee bread. Samples were prepared using the acetolysis method and stained using safranin. The research findings indicate the presence of 23 identified flowering plant species in the vicinity of the meliponiary, along with their identification in bee bread. However, only 12 species were identified in honey. Coconut pollen exhibited the highest percentage, accounting for 44.8% of honey and 38.13% of bee bread, categorizing it as a secondary pollen type.

Identification of pollen as afood resource for honey bees (Apis binghami) in the village of Bonto Manurung, District of Tompobulu, Regency of Maros

The endemic Sulawesi giant honey bee, Apis binghami, cannot be domesticated like other domesticated Apis genus bees. This bee is foraging for sources of nectar and pollen from plants around the tree where it is nesting. The purpose of this study is to identify the types of plant pollen in bee bread and honey as a means of identifying the food source of A. binghami forest bees and analyzing the category of honey they produce. The method used to extract pollen from honey and bee bread was acetolysis, an Erdtman method. The research found nine types of plant pollen in bee bread and seven in honey as food sources for A. binghami from samples collected from Bonto Manurung Village, Maros Regency. Aren palm (Arengan pinnata) pollen had the highest percentage frequency as a secondary pollen type group, along with mango (Mangifera sp.) and cotton wood tree (Ceiba petandra). Other types of plant pollen were classified as important minor pollen type and minor pollen type, resulting in honey from the hunting location of Bonto Manurung Village being categorized as multifloral honey.

Melissopalynological analysis and floral spectra of Apis mellifera scutellata Lepeletier bees in different agroecologies of southwest Ethiopia

The availability of bee forage limits honeybee productivity and is very important for beekeepers. Therefore, the current study aimed to identify the major botanical resources of honeybee, A. mellifera scutellata, in Southwest Ethiopia. Between October 2019 and October 2020, 69 group discussions (8–12 beekeepers), field observations, and pollen analysis were used to collect data. A total of 72 honey samples were collected from five districts at different seasons for pollen analysis. Most of the honey samples tested (93.06%) were multifloral, while 6.94% were monofloral. Melissopalynological analysis indicated that Eucalyptus camaldulensis (52.02%) was the predominant pollen type and is considered monofloral honey. Terminalia spp. (25.96%), Guizotia spp. (17.80%), and Bidens spp. (17.61%) were secondary pollen types and classified as multifloral honey. Terminalia spp., Guizotia spp., Vernonia spp., Bidens ssp., Plantago spp., and E. camaldulensis were pollen types recorded in honey samples in all agroecologies. Beekeepers ranked Schefflera abyssinica, Vernonia amygdalina, and Cordia africana as the first source of pollen and nectar for honeybees in highland, midland, and lowland, respectively. Additionally, V. amygdalina, Coffea arabica, Croton macrostachyus, and C. africana were commonly observed bee flora in all agroecologies. Honey bee management, such as bee forage shortages, the occurrence of brood and swarming, varied significantly (P < 0.05) among different agroecologies. In the present study, 53 honeybee plants were identified as pollen and nectar sources for honeybees. Various herbs (41.50%), trees (30.20%), and shrubs (28.30%) played a major role in honey production. Thus, beekeeping should be integrated with vegetation conservation for livelihood improvement and food security. Furthermore, existing bee flora should be cultivated in areas to increase the harvesting of honeybee products and improve the apiculture industry.

Palynological characterisation of palm honey (Sabal yapa) produced in Yucatan (Mexico)

The palm honey (Sabal yapa C. Wright ex Becc.) (Sabal honey henceforth) is one of 22 unifloral honeys recognised in the Yucatan Peninsula. This honey is harvested in February and March when Sabal yapa bloom but encompasses other important melliferous plants during the harvest season. A melissopalynological study of 24 honey samples from Tizimín, Yucatan (Mexico) was used to determine if Sabal honey is monofloral or multifloral, and to investigate the pollen contribution of other plants. Consequently, we determined the plant resources foraged by Apis mellifera. After analysis, 54 different pollen types were identified with the number of pollen types per honey sample ranging between nine and 21, with a mean of 14.75. Asteraceae and Fabaceae were the most diverse families and represented the highest percentage of contribution in pollen spectra. Sabal yapa pollen had a mean content of 56.9% (with a range of 45.4% to 84%). Bursera simaruba, Haematoxylum campechianum, Piscidia piscipula and Viguiera dentata were categorised as secondary pollen. Important minor pollen corresponded to Caesalpinia gaumeri, Ceiba pentandra, Pisonia aculeata, Thouinia paucidentata, and Trixis inula. Pollen composition revealed details of not only the rich native flora that accompanies Sabal yapa, but traditional human activities that occur around the apiaries. As expected, pollen of nectariferous species predominate in the samples, but also a number of nectarless species were found. Honeybees foraged mostly in trees present in remnants of primary vegetation, or at its different succession stages. Sabal honey could be labelled as monofloral.

Do egg cell‐secreted aspartic proteases promote gamete attachment?

During the double fertilization process of flowering plants (angiosperms), pollen tubes transport a pair of immobile sperm cells towards and inside the embryo sac for fusion with egg and central cell, respectively. Male-female gamete interactions during fertilization are critical for reproductive success and seed development, and thus have interested biologists since decades. Compared to animals, little is known about gamete interaction mechanisms in angiosperms. This article is protected by copyright. All rights reserved.

Response to Zhang et al., 'do egg cell-secreted aspartic proteases promote gamete attachment?'

In angiosperms, the molecular mechanism controlling polytubey/polyspermy block and fertilization recovery was not unraveled until recently (Zhong et al., 2022), which can be described as follows: Five pollen tube-expressed RALF peptide ligands, perceived by the receptor complex composed of three receptors FER/ANJ/HERK1 at the septum, establish the polytubey block at the septum so that only one pollen tube is allowed to emerge from the septum to target the ovule for fertilization. Pollen tube rupture releases the two sperm cells and fertilization is completed within 20 minutes. This article is protected by copyright. All rights reserved.

Melissopalynological Characterization of Honey Samples from Southeastern, Nigeria

The identification of plants in which the bees forage is key in establishing bee farms and increasing honey production. In this study pollen analysis of honey samples from the southeastern part of Nigeria was carried out to ascertain their floral sources and ecological origin. The honey samples were acetolyzed and microscopically studied to determine the pollen types. A total of seventy-one pollen types belonging to forty-one families of plants were identified. The honey samples were dominated by pollen grains from the families of Arecaceae, Euphorbiaceae, Myrtaceae, Irvigiaceae, Fabaceae, Combretaceae/Melastomataceae, and phyllanthaceae. Some of the dominant pollen grain identified include Elaeis guineensis, Alchornea cordifolia, Hymenocardia acida, Ocimum gratissimum, Syzygium guineense, Nauclea latifolia and Afzelia africana. Out of the six samples studied Njikoka sample was monofloral having Mimosa pigra as predominant pollen while Ayamelum, Ekwusigo, Nsukka, Ezeagu, and Udenu samples are multifloral containing Elaeis guineensis, Phyllanthus sp., Piliostigma reticulatum, Irvingia sp., Alchornea cordifolia, and Lannea sp. as major secondary pollen. All the samples analyzed have Elaeis guineensis in common except Ezeagu, indicating that these plants are present in all five locations. These results can also be used as a tool in the geographical identification of Southeastern Nigeria honey from other geopolitical zones.

RALF peptide signaling controls the polytubey block in Arabidopsis.

Fertilization of an egg by multiple sperm (polyspermy) leads to lethal genome imbalance and chromosome segregation defects. In Arabidopsis thaliana, the block to polyspermy is facilitated by a mechanism that prevents polytubey (the arrival of multiple pollen tubes to one ovule). We show here that FERONIA, ANJEA, and HERCULES RECEPTOR KINASE 1 receptor-like kinases located at the septum interact with pollen tube-specific RALF6, 7, 16, 36, and 37 peptide ligands to establish this polytubey block. The same combination of RALF (rapid alkalinization factor) peptides and receptor complexes controls pollen tube reception and rupture inside the targeted ovule. Pollen tube rupture releases the polytubey block at the septum, which allows the emergence of secondary pollen tubes upon fertilization failure. Thus, orchestrated steps in the fertilization process in Arabidopsis are coordinated by the same signaling components to guarantee and optimize reproductive success.

Pollen analysis of honeys from Yığılca region (Düzce), Turkey

The aim of this study is to determine the plant species preferred by Apis mellifera L., which is a valuable genotype in terms of vitality and high honey production. For this purpose, seven honey samples from Yığılca region in Düzce (Turkey) were examined for pollen analysis. As a result of the pollen analysis on these samples, it was determined that Yığılca local honeybee use pollen grains of 43 different taxa from 26 families. Six samples of honey were unifloral (&gt; 45% pollen of one taxon in sample) with four being unifloral for Rhododendron ponticum and two for Castanea sativa. One sample of honey was classified as multifloral with the percentages of secondary and rare pollen groups. The honeys had contained 14 to 30 different types of pollen. The average number of pollen types per honey was 21. The dominant groups of pollen grains were determined as Rhododendron ponticum in 4 samples and Castanea sativa in 2 samples. Secondary pollen components were from 3 taxa: Fagus orientalis, Rhododendron ponticum and Quercus sp. Four pollen types occurred as ‘minor’ types and pollen grains of 37 taxa were in rare quantities. Asteraceae, Fabaceae, Fagaceae, Lamiaceae and Rosaceae were the most represented families in honey samples.

Melissopalynological Analysis of Forest Honey from North Malaysia

Honey is a natural product widely used by humans due to its sweet taste and health benefits produced by bees from nectar and honey dew of various plants. To establish and increase the production of honey one must know the plants that take part in the production of honey. In this study pollen analysis of forest honey samples from northern part of Malaysia was carried out to determine the botanical sources playing role in the production of honey in that region. The pollen samples were acetolyzed and identified microscopically. Out of the three samples studied Baling sample was unifloral having Mimosa scabrella as predominant pollen while Jeli and Gerik samples are multifloral containing Tipo myrcia and Elais guineensis as major secondary pollen. Fabaceae family represented four pollen types and accounted 80% of pollen in Baling sample and 34 % in Gerik sample while completely absent in Jeli sample. These results showed the dominance of plants from Fabaceae family in honey production. All the samples analysed have Albizia falcataria, Eupatorium sp., Sparganium typha, Tilia sp. and Tipo myrcia in common indicating that these plants are present in all the three places and these results also can be used as a tool in geographical identification of North Malaysian honey from others.

Pollen analysis of summer honeys from Prayagraj District, Uttar Pradesh, India

Eighteen Apis dorsata Fabricius summer honey samples collected from Prayagraj District (Uttar Pradesh) during the summer season were analysed for pollen content. A total of 43 pollen types belonging to 26 plant families were found in these samples. Five of the 18 honey samples were found to be unifloral; 13 were multifloral. In terms of frequency, pollen of Syzygium cumini, Azadirachta indica and Coriandrum sativum were recorded as predominant pollen types, 11 pollen types as secondary pollen types, 23 as important minor pollen types, and 38 as minor pollen types. The Asteraceae family showed the highest frequency of occurrence. Four pollen types were recorded in more than 50% of the honey samples: Ageratum conyzoides, Bombax ceiba, Azadirachta indica and Syzygium cumini. Absolute pollen type counts per 10 g of honey samples ranged from group II to group V. The aim of determining and evaluating the pollen data was to infer the flora visited by the honeybees during the summer season in Prayagraj District. The findings were correlated with the pattern of vegetation in the vicinity of the bee hive sites during honey production. The study indicates that Prayagraj District has good potential for beekeeping ventures, due to the high diversity of nectar- and pollen-producing taxa during the summer season.

Secondary pollen presentation: More than to increase pollen transfer precision

AbstractPollination precision and efficiency have been deemed to be important driving forces in floral evolution. Herkogamy reduction is a main mechanism to increase pollination precision. Secondary pollen presentation (SPP), by which pollen is presented on other floral organs especially pistils, has been widely accepted as a special mechanism to increase pollen transfer precision through spatial reduction of the anther–stigma distance, that is, minimized herkogamy. This overlooks a potential driving force, that is expanding the pollination niche through converting pollen thieves and nectar robbers into effective pollinators. We selected two species as study models with typical pistillate SPP, Pavetta hongkongensis Bremek. (Rubiaceae) and Scaevola taccada (Gaertn.) Roxb. (Goodeniaceae). In both species, two distinct pollinator functional groups were recognized. Short‐tongued bees and flies fed on pollen on stigmas but also stole pollen from anthers and robbed nectar, whereas long‐tongued hawkmoths and butterflies only collected nectar. Emasculation had no influence on long‐tongued pollinators, but significantly decreased the visitation frequency of short‐tongued visitors and fruit set, compared to intact flowers, demonstrating short‐tongued visitors did not effectively pollinate and acted merely as pollen thieves or nectar robbers when SPP was absent. Data from the two plant species clearly indicated pistillate SPP has additional adaptive advantages of converting ineffective visitors into pollinators and consequently widening the pollination niche, which could help plants overcome environmental stochasticity. Our results suggest that multiple selective forces drive the evolution of SPP and the minimization of herkogamy.

Reproductive strategies of the Macroptilium lathyroides (Papilionoideae: Phaseoleae) explain the success of ruderal species in anthropized environments

Abstract Ruderal plants are important they are used for animal (e.g., beekeeping/pasture) and human food. Many of these plants present multiple reproductive strategies that ensure that they remain in disturbed environments. Therefore, we investigated the sexual reproduction and regeneration by regrowth of the forage ruderal Macroptillium lathyroides in an anthropized area to support management of this species after cutting or grazing and determine its requirements for seed production and conditions for commercial use. We assessed the occurrence of reproduction through regeneration and species dependence on pollinators. M. lathyroides has an axial underground system capable of regrowth but not propagation post-cut. Its flowers last about eight hours and are papilionate, asymmetrical, hermaphrodite, nectariferous, vinaceous and diurnal. They present secondary pollen that is transferred to the trichomes of the style. The species is self-compatible and presents spontaneous self-pollination. The small bee Exomalopsis cf. auropilosa, was the only pollinator since it activated the brush-type pollination mechanism while gathering nectar/pollen. The species depends on seeds to propagate or maintain a seed bank, since all plants do not regrow after cutting. Thus, sexual reproduction is necessary, but pollinators are not since it is not pollinator independent.

Исследование влияния пыльцевых зерен на цвет меда из цветков Melilotus officinalis (L.) Pall.

Introduction. According to the Federal State Statistics Service, the Siberian Federal district produced 8,464.06 tons of natural polyand monofloral honey in 2019. The share of the Altai region was 45.37%, Krasnoyarsk region – 7.8%, regions, Omsk – 7.0%, and Novosibirsk – 6.3%. The color of honey is one of the main identifying characteristics of products. It largely depends on the chemical composition of pollen grains of honey plants. Therefore, it is relevant to study the color of honey from the nectar of Melilotus officinalis (L.) Pall.&#x0D; Study objects and methods. The research featured honey samples produced from the nectar of Melilotus officinalis (L.) flowers. The honey was centrifuged and pumped in 2018 on the territory of the Altai region. The research involved standard methods, as well as an authentic method for determining the dominant pollen grains. The method was based on preserving the morphological features of pollen grains and did not change their spatial location, thus making it possible to determine their real content in honey.&#x0D; Results and discussion. The honey color was affected by pollen grains of honey-bearing plants: 1) Melilotus officinalis (L.) Pall. (84.89%) &gt; Fagopyrum tataricum (L.) Gaertn. (1.0%) &gt; Convolvulus arvensis L. (0.97%) &gt; Origanum vulgare (L.) (0.97%) &gt; Brassicaceae Burnett, nom. cons. (11.20%); 2) Melilotus officinalis (L.) Pall. (49.24%) &gt; Dracocephalum nutans L. (7.58%) &gt; Trifolium pratense L. (9.09%) &gt; Brassicaceae Burnett, nom. cons. (18.18%) &gt; Sonchus arvensis L. (2.07%); 3) Melilotus officinalis (L.) Pall. (54.05%) &gt; Helianthus annuus L. (14.87%) &gt; Linaria vulgaris Mill. (2.70%) &gt; Arctium tomentosum Mill. (4.05%) &gt; Trifolium repens L. (8.47%) &gt; Brassicaceae Burnett, nom. cons. (10.81%). Color and nutritional value depended mostly on two factors. The first factor was represented by flavonoid compounds (leucoanthocyanins, catechins, flavonols, etc.) of pollen grains of Melilotus officinalis (L.) Pall., Brassicaceae Burnett, nom. cons., and Helianthus annuus L. Their contents were 5.2, 3.1, and 2.8%, respectively. The other factor involved carotenoids – Trifolium pratense L., Trifolium repens L. and Origanum vulgare (L.). Their contents were 50.0, 37.3, and 28.7 mg/kg, respectively.&#x0D; Conclusion. The research featured honey from the flowers of Melilotus officinalis (L.) Pall. obtained from the South of the Siberian Federal District. Its color proved to be one of the main sensory properties necessary for establishing the botanical profile of the plants. The color depended on the secondary pollen grains of honey plants, containing flavonoid compounds and carotenoids.

Pollen Spectrum and Foraging Plants for the Red Dwarf Bee in Jordan

Pollen spectrum of honey, and pollen content of the honey sac of the red dwarf honeybee (Apis florea F.), which was discovered recently in Jordan, were studied. Pollen diversity and pollen density in these samples, which were collected from two sites in Jordan, were investigated. A total of 4399 pollen grains were counted and classified in the honey of A. florea. 2667 pollen grains, or 60.63% of total pollen, were obtained from Centaurea hylolepis Bioss., which is considered to be the Dominant Pollen (DP), and the studied honey was monofloral. About 1541 pollen grains, or 35.03% of the total, were collected from Family Caryophyllacea and considered to be a Secondary Pollen (SP) source. Cardania draba (L.) was considered a Minor Pollen (MP) source with 2.07% abundance, followed by Ecualyptus sp. (0.68%); Acacia cyanophylla Lindl. (0.59%); Leopoldia desirticola (Rech.f.) Feinbrun (0.48%); Salvia lonigera Poir. (0.39%); and Sambucus racemosa L. (0.14%). The plant diversity or number of plant species foraged by small bees was eight. While the plant diversity in honey sac content of the small bee from another site, El-Akaba, was nine. Centaurea sp., Echinops sp. and Erodium sp. were considered as Secondary Pollen (SP) sources, with percent abundances of 33.99, 23.60% and 16.23%, respectively. The following Important Minor Pollen sources (IMP) and their (abundance %) and classification were as follows: Asphodelus sp. (6.96%); Phoenix sp. (5.94%); and Rubus sp. (5.66%). Minor Pollen (MP) sources were: Diplotaxis sp. (1.6%); Ecobllium sp. (1.16%) and Sencio sp. (0.16%).

Palynological and physicochemical properties of multifloral honey produced in some regions of Algeria

This study aimed to determine the palynological and physicochemical properties of multifloral honey collected from different regions of Algeria. A total of 24 different honey samples have been analysed for various physicochemical parameters (moisture, electrical conductivity, pH, acidity (free, lactone and total), Hydroxymethylfurfural (HMF), proteins, color, total sugars, fructose, glucose, sucrose, and fructose/glucose ratio). The results obtained in the present study show the variability of the chemical composition of the honey samples. The results of the study indicated that most of the honey samples were of good quality, and were found to meet all major international honey specifications. From the palynological point of view, 62.5% of the samples had a moderate amount of pollen grains per 10 gram of honey (class II); seven samples (29.16%) were rich in pollen (class III), and only two samples (8.33%) had a low pollen concentration (class I). A total of 94 pollen types, belonging to 48 botanical families, were identified. The pollen types identified per sample vary from 15 to 37, with an average of 27 types. The best represented families were Fabaceae, Boraginaceae, and Asteraceae, which present in all the samples. The best represented secondary pollen types were Echium sp., Trifolium sp., Peganum harmala, Eucalyptus sp., Olea europaea, Chenopodium sp., Ononis natrix, and Ziziphus lotus. The qualitative pollen analysis demonstrated the important participation of nectarless plants in the makeup of the honeys, especially Chenopodium sp., and Olea europaea.

Palynological characterisation of sedra honeys (Ziziphus lotus) produced in Algeria

A melissopalynological study was carried out on 46 samples of Ziziphus lotus honey from Laghouat and Djelfa region (central Algeria). The number of pollen types identified per honey sample ranges between nine and 39 with a mean of 24. These correspond to 52 botanical families with 79 different pollen types in the whole samples. Asteraceae and Fabaceae families were present in all the samples where as Apiaceae, Brassicaceae and Nitrariaceae (Peganum harmala) were identified in more than 90%. Other plant families as Boraginaceae, Cistaceae, Myrtaceae, Oleaceae, Salicaceae or Urticaceae were identified in more than 50% of the samples but frequently as minor pollen. Ziziphus lotus pollen had a mean content of 68.9% (with a range of 45.3% to 93.4%). The secondary pollen types were Ononis natrix, Peganum harmala, Brassica napus, Echium and Olea europaea. Regarding the important pollen it is highlighted the presence Lotus t., Eucalyptus, Pimpinella anisum t., Trifolium t., Eryngium campestre t., Centaurea t., Galega officinalis t., Citrus or Scrophularia t. The sedra honeys of the studied region are characterised by their high content in pollen grains with a mean content of 188 403 grains/10 g. The presence of some pollen types in the pollen spectra of honeys such as Peganum harmala, Thapsia garganica, Launaea, Muscari comosum, Carthamus or Limonium bonduellei together several Asteraceae as Centaurea, Taraxacum, Carduus, Artemisia and Matricaria was proposed as geographical markers of this honey type.